Viruses cause diseases by penetrating the host cell membrane and transferring its genetic material to the cell compartment to hijack its cellular machinery. Some viruses are protected by an envelope, which allows the virus to bind to specific target cells and via proteins to fusion the envelope with the cell membrane and thus deliver its genome. However, it remains poorly understood how non-enveloped virus, such as the polio virus, which in severe cases where the central nervous system becomes infected results in paralysis, penetrates the cell membrane.

Researchers from Harvard University, USA, found a novel way of using real time fluorescence microscopy to follow single polio virus particles as they infect the cell. They found that this process requires energy, but surprisingly does not involve endocytic pathways. Instead the genome is transported into the cell by vesicles located very close to the cell surface.

Brandenburg, B., Lee, L. Y., Lakadamyali, M., Rust, M. J., Zhuang, X. and Hogle, J. M. (2007) Imaging poliovirus entry in live cells. PLoS Biology 5: 1543-1555.